Folding device comprising upstream or downstream blade shafts or comparable tool shafts

ABSTRACT

In a device ( 10 ) for folding a paper web ( 28 ) comprising a pair of tool shafts ( 24, 26 ) carrying circular knives ( 70, 74 ) which pair is arranged upstream or downstream of its folding rollers ( 16, 18, 20, 22 ), the circular knives ( 70, 74 ) and/or the transport roller units ( 40, 50 ) can be rotatively driven for transporting the paper web at the same web running speed in the region of the tool shafts ( 24, 26 ) and in the region of the folding rollers such that the speed components of the circular knives ( 70, 74 ) in the web running direction are at least not lower, preferably higher than the web running speed of the paper web ( 28 ).

TECHNICAL FIELD

The invention relates to a device for automatically folding paper webs.Upstream or downstream of such folding devices using the knife foldingor the buckle folding technology there are longitudinal cutting meansprovided, for example, for bringing an already folded sheet or a sheetto be folded subsequently into the correct width by cutting offlongitudinal margins or for cutting the product into a plurality ofpanels.

PRIOR ART

It is known to equip folding devices, such as, for example, bucklefolding devices, with upstream or downstream tool shafts. These toolshafts can be equipped for longitudinal cutting, but also forperforating or creasing. For longitudinal cutting, upper and lowerknives can be used which are supported fixedly against rotation on acorresponding upper and lower shaft, respectively. By means of suchcircular knives, two of which are cooperating in each case, the web canbe cut in one shearing cut in the longitudinal direction, i.e. in therunning direction of the web. Due to manufacturing tolerances of thecutting knives it is very difficult to bring the cutting gap between therespective upper and lower knives to zero, if possible, in order toachieve the highest cutting quality possible. It is known to axiallydisplace the circular knives on the respective upper or lower knifeshaft in order to adjust the width of the cutting gap. In order to avoidundesired bulging of the web, the conveying speed of the paper webbetween the tool shafts and the folding shafts of the folding devicemust be exactly the same. The shearing-cut cutting principle impliesthat the diameters of the upper and lower knives are somewhat largerthan the transport rollers which are provided on each cutting shaft andconvey the paper web between them. However, due to this overlap, thecutting knives have—in spite of their higher circumferential speed dueto their larger diameters—at the cutting point a somewhat lower speedcomponent in the running direction than the paper web. In the case of ashearing cut, this leads to the fact that the paper web is kind ofpulled through the cutting knives, which leads to a very bad cuttingquality especially in the case of thin paper.

DESCRIPTION OF THE INVENTION

The object underlying the invention is, starting from the prior art asmentioned above, to form the tool shafts, such as, in particular, knifeshafts, which are arranged upstream or downstream in folding devices,such that a shearing cut of the highest quality possible or alongitudinal processing comparable thereto is achieved.

This invention is described in independent claim 1, 11 or 13.Appropriate further developments of the invention are the subject-matterof the respective dependent claims relating thereto.

According to a first embodiment of the invention, the lower circularknife is, for example, supported in a freely movable manner on its knifeshaft, while the associated upper circular knife is supported fixedlyagainst rotation on its upper shaft. The lower, rotatively driven knifeshaft is connected directly or indirectly through a transmission to theupper shaft such that the upper knife shaft is given a comparably higherrotational speed. This can also be achieved by a further own drive forthe upper knife shaft. This higher rotational speed of the upper shaftresults in the fact that the upper circular knife has a correspondinglyhigh rotational speed. By laying the upper circular knife against thelower circular knife this high rotational speed can be transferred tothe lower circular knife supported in a freely rotatable manner on itslower shaft. In order to achieve this, the lower circular knife can alsobe laid against the upper circular knife. In this way, it is guaranteedthat the two cutting knives in the cutting point with the paper web havea higher speed component in the running direction of the web than theweb itself, so that a shearing cut of high quality can be produced.

In order to guarantee an equally high web speed between the tool shafts,as, in particular, the knife shafts and the folding shafts of thefolding device, further provisions can be made to arrange the transportrollers fixedly against rotation on the tool shaft on which the circularknife is supported in a freely rotatable manner. In contrast thereto,the other transport rollers arranged on the other tool shaft aresupported in a freely rotatable manner. Herein it is irrelevant which ofthe tool shafts, the upper or the lower one, is driven with higherspeed.

It has been shown that in the case of the known tool shafts and thecircular knives mounted thereon an increase of the rotational speed byabout 20 percent is enough to receive with certainty a leading, pullinglongitudinal cut through the paper web.

According to another embodiment of the invention, such a pullinglongitudinal cut can also be achieved by arranging a correspondingtransmission between the one shaft to be rotated by any kind of driveand one of the two circular knives. It would also be possible to causeone of the two or both circular knives by means of separate drives torotate at a higher speed as compared to the rotatively driven shaft(s).

While the above-mentioned embodiments are based on the fact that atleast one of each two tool shafts carrying circular knives cooperatingas cutters is driven at the same rotational speed at which the othershafts present in the folding unit are driven, in order to be able toconnect at least one of the transport rollers abutting on the paper webfrom above and from below fixedly against rotation to this tool shaftand thus to guarantee a uniform transport of the paper web also in thearea of the tool shafts, according to another embodiment of theinvention, each two circular knives cooperating as cutters can besupported fixedly against rotation on their tool shafts. In contrast,the one or the two transport rollers abutting on the paper web fromabove and from below, respectively, are herein supported in a freelyrotatable manner on the respective tool shafts. In this case, thetransport rollers can be rotatively driven such that they transport thepaper web conveyed between them at the desired web running speed towardsthe folding shafts or away from the folding shafts. Herein the toolshafts can be rotatively driven at a correspondingly higher speed sothat the above-mentioned shearing cut of higher quality can be produced.Manufacturing a transport roller which is supported in a freelyrotatable manner can be done using a simpler design and is thuseconomically more advantageous than a comparable design for a circularknife being supported in a freely rotatable manner. The transportrollers abutting on the paper web from above or from below,respectively, can be correspondingly driven by auxiliary shafts, forexample. It would also be possible to drive only one of each twotransport rollers correspondingly and to pull along the other transportroller quasi through their abutment on the paper web.

The cutting quality of the longitudinal cut(s) to be produced in a paperweb in connection with a folding device can also be increased bybringing the cutting gap between the upper and lower knives to theamount of zero, if possible. As already mentioned above, in this respectit is known to push the circular knives axially together on the knifeshafts. Due to manufacturing tolerances, however, a cutting gap ofhigher or lower width cannot be avoided. In accordance with theinvention, a cutting gap of minimal width can be produced by pressingone of the opposing circular knives through a spring element against themating knife. In a first exemplary embodiment, the circular knifeattached fixedly against rotation on a shaft is loaded by means of aspring element in the axial direction such that its revolving rim alwaysabuts in frictional engagement on the mating knife. As shown by theembodiments illustrated in the drawings, this spring element canpreferably be an elastically deformable ring, such as, in particular, arubber ring or else a steel spring or another spring element.

Further advantages and features of the invention can be gathered fromthe features further described in the claims as well as from thefollowing exemplary embodiment.

SHORT DESCRIPTION OF THE DRAWINGS

The invention will be hereinafter described and explained in more detailby way of the exemplary embodiment illustrated in the accompanyingdrawings, in which

FIG. 1 is a view of two knife shafts, seen in the running direction of apaper web, according to a first embodiment of the invention, comprisinga circular knife arranged fixedly against rotation on a first knifeshaft and another circular knife arranged in a rotatable manner on asecond knife shaft;

FIG. 2 is a schematic side view of a folding device comprising upstreamknife shafts;

FIG. 3 a view of two knife shafts, seen in the running direction of apaper web, according to a second embodiment of the invention, comprisingtwo circular knives, each of which is arranged in a freely rotatablemanner;

FIG. 4 a view of two knife shafts, similar to FIG. 3, comprising twodriven auxiliary shafts for driving two circular knives according to athird embodiment of the invention;

FIG. 5 a view of two knife shafts, seen in the running direction of apaper web, according to a fourth embodiment of the invention, comprisingtwo circular knives arranged fixedly against rotation.

WAYS OF CARRYING OUT THE INVENTION

In accordance with FIG. 2, a buckle folding device 10 has a first upperfolding pocket 12 and a second lower folding pocket 14. A first upperfolding roller 16 and a second lower folding roller 18 are arrangedupstream of the first folding pocket 12. A third upper folding roller 20and a fourth lower folding roller 22 are arranged downstream of thesecond folding pocket 14. Such an arrangement of a buckle folding device10 is known.

In accordance with FIG. 2, in the present exemplary embodiment, an uppercutting and transport roller 24 and a lower cutting and transport roller26 are arranged upstream of the first and second folding rollers 16, 18.A paper web 28 is passed in the web running direction 30 through the twocutting and transport rollers 24, 26 and subsequently through the bucklefolding device 10, wherein a first loop 32 is produced by the fact thatthe paper web 28 runs into the first folding pocket 12, and subsequentlya second loop 34 is produced by the fact that the folded paper web 28runs into the second folding pocket 14. The first loop 32 is folded bythe second and third folding rollers 18, 20 to form a first fold, andsubsequently the second loop 34 when passing between the third foldingroller 20 and the fourth folding roller 22 is folded to form a secondfold. This kind of longitudinal cutting of a paper web 28 and subsequentfolding is per se known.

A lower transport roller unit 40 is mounted fixedly against rotation onthe lower cutting and transport roller 26 shown in FIG. 1 by means of ascrew 42. The outside of the transport roller unit 40 is provided with arubber inlay 44. This lower transport roller unit 40 is associated withan upper transport roller unit 50. The outer ring 58 of this transportroller unit 50 is supported in a freely rotatable manner with respect tothe upper shaft. For this purpose, a retainer jaw 52 of this transportroller unit 50 is supported fixedly against rotation on the upper shaft24 by means of a screw 54. The retainer jaw 52 carries a ball bearing 56arranged fixedly on the retainer jaw 52 through a blocking ring 57 inthe axial direction 59, wherein the outer ring 58 is supported on theball bearing 56, the outside of the outer ring 58 being provided with arubber inlay 45. The paper web 28 runs between the two rubber inlays 44,45 of the lower and upper transport roller unit 40, 50.

A lower retainer jaw 60 is supported fixedly against rotation in theaxial direction laterally next to the lower transport roller unit 40 onthe lower shaft 26. The retainer jaw 60 is surrounded by a ball bearing64 carrying an outer retaining ring 66. Thus the retaining ring 66 issupported in a freely rotatable manner on the retainer jaw 60. The ballbearing 64 is arranged fixedly at the lower retainer jaw 60 by means ofa blocking ring 61 in the axial direction 59. The lower circular knife70 is held in the retaining ring 66 in a clamped manner between arecessed shoulder 67 of the retaining ring 66 and a distance piece heldby a blocking ring 69 in the axial direction 59 against the retainer jaw66. Due to the ball bearing 64 this lower circular knife 70 is, in thesame way as the retaining ring 66, supported in a freely rotatablemanner on the lower retainer jaw 60 and thus on the lower shaft 26.

The lower circular knife 70 cooperates with an upper circular knife 74.This upper circular knife 74 is supported fixedly against rotation on anupper retainer jaw 76 which is attached fixedly against rotation on anupper shaft 24 by means of a screw 78, wherein the upper circular knife74 is loaded by an elastic ring 80 in the axial direction 59, i.e. inthe longitudinal direction of the two longitudinal axes 82, 84 of theupper shaft 24 and the lower shaft 26.

Thus the elastic ring 80 presses in the axial direction 59 against theupper circular knife 74. By means of this pressure force the uppercircular knife 74 is laid in the axial direction 59 laterally in apressing manner against the lower circular knife 70, as shown in FIG. 1.The two circumferential rims of the two circular knives 70, 74 thusproduce a shearing cut with a cutting gap, the size of which approacheszero.

In this way a clean longitudinal cut can be produced, and thus, forexample, a lateral margin 83 can be separated with a clean quality cutfrom the remaining paper web 28. Each cutting rim of the two circularknives 70, 74 has a hollow grinding not shown in the figure. Thisenables to achieve a clean separation cut even if the circular knives70, 74 have lost their exactly perpendicular alignment with respect tothe axial direction by a small amount, for example, due to a smallclearance in the ball bearing 64.

The elastic ring 80 (rubber ring) is held laterally framed by a pressring 81. The press ring 81 has an internal thread, and the upperretainer jaw 76 has an external thread, so that the press ring 81 can bescrewed onto the retainer jaw, whereby the elastic ring 80 can bebiased. The press ring is fixed in its adjusted position by means of ascrew 85 which can radially screwed into the upper retainer jaw 76.

In order to produce this shearing cut as a leading pulling cut, a lowergear 90 having 24 teeth in the present case is attached fixedly againstrotation on the lower shaft 26, which is actively driven in a rotatablemanner. This lower gear 90 is in meshing engagement with an upper gear92 having, for example, 20 teeth and being attached also fixedly againstrotation on the upper shaft 24. The transmission consisting of these twogears 90 and 92 causes the upper shaft 24 to have a rotational speedwhich is higher by 20 percent than that of the lower shaft 26. Thismeans that the upper circular knife 74 attached fixedly against rotationon the upper shaft 24 has a correspondingly increased rotational speed,which is transferred by this upper circular knife 74 onto this lowercircular knife 70 by its frictionally engaging abutment on the lowercircular knife 70. The lower circular knife 70 adopts this increasedrotational speed, since it is supported in a freely rotatable mannerthrough the ball bearing 64 on its lower shaft. In this way asufficiently increased rotational speed of the circular knives 70, 74 ascompared to the running speed of the paper web 28 can be guaranteed. Incontrast thereto, the running speed of the web 28 is not increased. Therunning speed of the web 28 is based on the rotational speed of thelower transport roller unit 40 attached fixedly against rotation on thelower shaft 26. The rotational speed of the lower transport roller unit40 is transferred through its rubber inlay 44 onto the upper transportroller unit 50 with the upper rubber inlay 45 being supported in afreely rotatable manner. The paper web 28 is thus transported throughthe two rubber inlays 44, 45 of the two transport roller units 40, 50 inthe web running direction at a speed determined by the rotational speedof the lower shaft 26. The lower shaft 26 is now driven such that thespeed of the paper web 28 corresponds to the speed which is also presentwhen the paper web 28 runs through the downstream folding rollers 16,18, 20, 22.

The embodiment shown in FIG. 3 of an upper and a lower cutting andtransport shaft 24, 26, between which the paper web 28 passed through isseparated with a longitudinal cut, differs from the embodiment shown inFIG. 1 in so far as not the two shafts 24, 26 are given differentrotational speeds by means of a transmission, but that by means of atransmission the one, in this exemplary embodiment, the lower shaft 26is connected directly to the—in this exemplary embodiment—upper circularknife 74.

A lower transport roller unit 40 is supported fixedly against rotationby means of a screw 42 on the lower cutting and transport shaft 26 inthe same way as in the case of the embodiment according to FIG. 1.

In the case of the embodiment according to FIG. 3, the lower circularknife 70 is also held by clamping in an outer retaining ring 66 in thesame way as in the case of the embodiment according to FIG. 1, whereinthe outer retaining ring 66 is in turn supported through a ball bearing64 in a rotatable manner on a lower retainer jaw 60 which is arrangedfixedly against rotation on the shaft 26 by means of the screw 62. Thesupport for the lower circular knife 70 is identical for the embodimentsaccording to FIGS. 1 and 3.

An upper transport roller unit 50.3 is arranged fixedly against rotationon the upper cutting and transport shaft 24. This upper transport rollerunit 50.3 corresponds to the lower transport roller unit 40. It isattached fixedly against rotation on the upper shaft 24 by means of ascrew 54. The paper web is passed between the transport roller units 40,50.3. Herein the rubber inserts 44, 45 of the two units 40, 50.3 abut ina pressing manner with frictional engagement from below and from above,respectively, on the paper web 28.

The upper circular knife 74 is supported fixedly against rotation in anouter retaining ring 94. The outer retaining ring 94, in turn, isattached in a rotatable manner through a double-track ball bearing 96 atan upper retainer jaw 98. The upper retainer jaw 98, in turn, isattached through a screw 100 at the upper shaft 24. The double-trackball bearing 96 is held by means of a locking ring 102 in anundisplaceable manner at the upper retainer jaw 98 and thus at the shaft24.

The upper circular knife 74 is held in a pressed manner in the axialdirection 59 between a stepped in shoulder 104 of the outer retainingring 94 and a press ring 81 screwed onto this retaining ring 94 andsecured by means of a screw 108. Herein an elastic ring 80 is arrangedbetween the upper circular knife 74 and the shoulder 104. This elasticring 80 (rubber ring) presses in the axial direction 59 laterallyagainst the upper circular knife 74. Thereby the upper circular knife 74is pressed laterally against the lower circular knife 70 and thus africtionally engaging abutment between the two circular knives 70, 74 isachieved in the same way as it is the case in FIG. 1.

The outer retaining ring 94 which is rotatable about the upper shaft 24has at its—in FIG. 3—left end region a sprocket 112 having 20 teeth inthe present exemplary embodiment. This sprocket 112 cooperates with agear 90 attached fixedly against rotation on the lower shaft 26. In thisexemplary embodiment the lower gear has 24 teeth. The lower shaft 26,which has been made to rotate by any kind of drive, transfers itsrotation to the lower gear 90. The lower gear 90 which is in meshingengagement with the upper sprocket 112 causes the sprocket 112 to rotatefaster by—in this exemplary embodiment—20 percent than the lower shaft26. This results in a rotational effect which is different from theembodiment according to FIG. 1. The rotation of the sprocket 112 acts onthe upper circular knife 74. This also causes the upper circular knife74 to rotate at a rotational speed which is higher by 20 percent thanthat of the lower shaft 26.

The rotational speed of the upper circular knife 74 is transferred tothe lower circular knife 70 by the frictionally engaging abutment of thetwo circular knives 70, 74, as it has already been described above inconnection with FIG. 1. In this way, in the paper web 28 a so-calledleading pulling longitudinal cut through the paper web 28 can beproduced.

In this embodiment the upper shaft 24 is dragged along through the twotransport roller units 40, 50.3; a separate rotational drive for theupper shaft 24 is dispensable. It would be possible to form the uppertransport roller unit 50.3, in the same way as in the case of theembodiment according to FIG. 1, like the transport roller unit 50 andthus freely rotatable relatively to the upper shaft 24. In this case theupper shaft 24 could remain at rest, without rotation.

The upper circular knife could also be made to rotate faster as comparedto the lower shaft 26 by means of any other drive instead of by means ofthe lower gear 90.

In the embodiment illustrated in FIG. 4, upper and lower transportroller units which are fixed against rotation are arranged on the twoshafts 24, 26, wherein an upper transport roller unit 50.3 and a lowertransport roller unit 40 are shown in the drawing. The paper web 28passes between the two transport roller units 40, 50.3, which correspondto the respective transport roller units of FIG. 3, wherein rubberinlays 44, 45 which are provided in each of the transport roller unitsabut thereon from below and from above in a pressing and frictionallyengaging manner.

An upper circular knife 74 is supported in a freely rotatable mannerabout the upper shaft 24 in the axial direction 59 next to the uppertransport roller unit 50.3. The upper circular knife 74 is supported ina freely rotatable manner through a ball bearing 64 on an upper retainerjaw 60.4, which is arranged fixedly against rotation on the upper shaft24. The retainer jaw 60.4 with its mount of the upper circular knife 74corresponds to the lower retainer jaw 60 arranged fixedly againstrotation on the lower shaft 26 in FIG. 1. The upper retainer jaw 60.4provided in the upper shaft 24 in FIG. 4 differs from the retainer jaw60 illustrated in FIG. 1 in so far as a sprocket 114 is attached fixedlyagainst rotation at the radial circumference of the outer retaining ring66 of the upper retainer jaw 60.4. This sprocket 114 cooperates with asprocket 116 provided on a gear 118. This gear 118 is attached fixedlyagainst rotation on an upper auxiliary shaft 120. The outer retainingring 66 of the upper retainer jaw 60.4 can be made to rotate in any waythrough the gear 118 and its sprocket 116 by means of a rotational drive(not shown in the drawing) for the auxiliary shaft 120. Incorrespondence with the above-mentioned embodiments, its rotationalspeed can then, for example, be selected to be higher by 20 percent thanthe rotational speed of the two transport roller units 50.3, 40 of thetwo shafts 24, 26.

The lower retainer jaw 60.5 provided on the lower shaft 26 correspondsto the upper retainer jaw 60.4 with the difference that instead of thedistance piece 68 of the upper retainer jaw 60.4 a distance piece 68.4is provided, which in the present exemplary embodiment has an angularshape and is supported in the axial direction through a (still present)locking ring 69 on the outer retaining ring 66. There is an elastic ring80 provided between the L-shaped distance piece 68.4 and the lowercircular knife 70. The lower circular knife 70 is pressed through theelastic ring 80 against the stepped in shoulder 67 of the outerretaining ring 66. In this way, the lower circular knife 70 is laid withfrictional engagement against the upper circular knife 74 in the axialdirection 59. Otherwise the lower retainer jaw 60.5 corresponds to theupper retainer jaw 60.4 in so far as a sprocket 114 is also attachedfixedly in the outer retaining ring 66. The sprocket 114 is in meshingengagement with a sprocket 116 of another gear 118 attached fixedlyagainst rotation on a lower auxiliary request 122.

In the present exemplary embodiment the rotational speeds of the twoauxiliary shafts 120, 122 are equally high. Since the transmissionratios of the gears 118 to the lower retainer jaw 60 and the upperretainer jaw 60.4, respectively, are identical, the two circular knives70, 74 also rotate with exactly the same rotational speed. Thisrotational speed is—as already mentioned above—higher by about 20percent than the rotational speed of the two shafts 24, 26. In this waya leading pulling longitudinal cut can be produced in the paper web 28using the two circular knives 70, 74.

The embodiment according to FIG. 4 can also be used to carry out alongitudinal cut in a middle portion of the paper web 28, since theupper and the lower retainer jaw 60.4, 60.5 have a finite distance 130and 132, respectively, from the paper web 28. In the case of theembodiment according to FIG. 3 this would be possible only if theclearance present in the axial direction 59 between the lower gear 90and the paper web 28 was large enough.

In the embodiment according to FIG. 5 the upper circular knive 74 issupported fixedly against rotation on the upper cutting and transportshaft 24, as it is the case in FIG. 1. Herein the upper circular knive74 is pressed against the—in FIG. 5 towards the left—outer left shoulder86 of the upper retainer jaw 76 by means of an interposed elastic ring80 by a press ring 81, which is screwed onto the upper retainer jaw 76attached fixedly against rotation on the shaft 24 by means of a screw78. The press ring 81, in turn, is held in its screwed-on position bymeans of a screw 85 screwed radially into the upper retainer jaw 76.

The lower circular knife 70 is also attached fixedly against rotation onthe lower cutting and transport shaft 26. Thus a lower retainer jaw 60.6is attached fixedly against rotation on the shaft 26 by means of a screw62. A press ring 81.5 is screwed in the axial direction onto this lowerretainer jaw 60.6, wherein the press ring 81.5 is retained in itsscrewed-on position by means of a screw 85 in its position at theretainer jaw 60.6. The press ring 81.5 in the axial direction pressesthe lower circular knife 70 directly against a—in FIG. 5 right—outershoulder 87 of the lower retainer jaw 60.6. The lower circular knife 70is held in an undisplaceable manner between the press ring 81.5 and theshoulder 87 of the retainer jaw 60.6

The two cutting and transport shafts 24, 26 are driven such that thepaper web 28 can be separated in the web running direction—using alongitudinal cut—by the two circular knives 70, 74, as it has alreadybeen mentioned above.

A lower transport roller unit 40.5 is supported in a freely rotatablemanner on the lower cutting and transport shaft 26. For this, its lowerretainer jaw 51 is arranged fixedly against rotation on this lower shaft26 by means of a screw 42. An outer retaining ring 66.5 is supported ina rotatable manner through a ball bearing 144 on the lower retainer jaw51. The rubber inlay 44 is attached at the outer retaining ring 66.5, asit is the case with the above-mentioned lower transport roller unit 40.Thus, the outer retaining ring 66.5 can be rotated relatively to thelower cutting and transport shaft 26.

A sprocket 146 radially protruding from the outer retaining ring 66.5 isprovided for rotating the outer retaining ring 66.5. This sprocket is inmeshing engagement with a gear 148 attached fixedly against rotation onthe auxiliary shaft 122, which is supported at a constant distance tothe lower shaft 26. Thus, the outer retaining ring 66.5 with its rubberinlay 44 can be rotatively driven at any desired speed by driving theauxiliary shaft 122 by means of the gear 148 and the sprocket 146.

A comparable freely rotatable support is also provided for the uppertransport roller unit 50.5. Herein an outer retaining ring 156 is heldthrough a retainer jaw 52.5 supported fixedly against rotation on theupper shaft 24 by means of a screw 54 through a ball bearing 56supported on the retainer jaw 52.5. A sprocket 148 is formed at theouter retaining ring 156 in a way comparable to the outer retaining ring66.5 of the lower transport roller unit 40.5, wherein the sprocket 148cooperates with a gear 150. The gear 150 is attached fixedly againstrotation on an auxiliary shaft 120. A rubber inlay 45 is attached at theouter retaining ring 156, as it is also the case in a comparable waywith the upper transport roller unit 50 (FIG. 1).

Through the auxiliary shaft 120 the outer retaining ring 156 and thusthe upper rubber inlay 45 can be given rotational speed, and the same istrue for the lower rubber inlay 44 through the auxiliary shaft 122.These rotational speeds are high enough for transporting the paper web28 held with frictional engagement between the two rubber inlays 44, 45at the desired web running speed through the area of the cutting andtransport rollers 24, 26. This web speed is equally high in the area ofthe cutting and transport shafts 24, 26 and the folding rollers (FIG.2).

In contrast thereto, the two circular knives 70, 74 can be driven, inthe present exemplary embodiment, at rotational speed which is higher byabout 20% (percent), so that the desired shearing cut of high qualitycan be produced in the paper web 28, as it has been mentioned above. Therotational speed of the two circular knives 70, 74 which is higher ascompared to that of the transport shafts is achieved by correspondingrotational drives for the two cutting and transport rollers 24, 26, onwhich the respective two circular knives 70, 74 are arranged fixedlyagainst rotation.

1-17. (canceled)
 18. A device for folding a paper web comprising lowerand upper tool shafts arranged upstream or downstream of foldingrollers, said lower tool shaft carrying at least one lower circularknife, and said upper tool shaft carrying at least one upper circularknife, wherein said lower and upper circular knives are arranged and canbe rotatively driven for cutting such that at least a longitudinal cutcan be produced in a running direction of said paper web in said paperweb running through said upper and lower tool shafts, and transportroller units for transporting said paper web through and between saidupper and lower tool shafts and towards said folding rollers and/or awayfrom said folding rollers and towards said upper and lower tool shaftsand through and between them, wherein said circular knives arerotatively driven such that speed components of said circular knives insaid web running direction are higher than said web running speed ofsaid paper web, rotational drives for at least one of said upper andlower tool shaft and for at least one of said folding rollers foldingroller are such that web running speeds of said paper web throughbetween said upper and lower tool shafts and through between saidfolding rollers are equally high, at least one upper circular knife issupported in a freely rotatable manner on said upper tool shaft, atleast one lower circular knife cooperating with said at least one uppercircular knife for cutting is supported in a freely rotatable manner onsaid lower tool shaft, and the upper and lower circular knives arerotatively driven at a higher speed with respect to said tool shafts, sothat each circular knife has a higher rotational speed as compared tothat of said tool shafts on which it is placed.
 19. The device accordingto claim 18, wherein a transmission is provided between at least onerotatively driven tool shaft and at least one circular of said circularknives.
 20. The device according to claim 18 wherein a transmissionbetween at least one of said circular knives and a rotatively drivenauxiliary shaft is provided.
 21. The device according to claim 18,wherein circular knives cooperating for cutting are pressed together inan axial direction.
 22. The device according to claim 18, wherein atleast one transport roller unit is arranged fixedly against rotation onone of said tool shafts, and at least one transport roller unit issupported in a freely rotatable manner or in a fixed manner on anotherof said tool shafts.
 23. The device according to claim 21, wherein anelastic element presses in said axial direction against one of saidcircular knives such that said one of said circular knives abuts withfrictional engagement against another of said circular knivescooperating with said one of said circular knives for cutting.
 24. Thedevice according to claim 23, wherein said elastic element is anelastically deformable ring, such as, in particular, a rubber ring or asteel spring.
 25. The device according to claim 18, wherein a cuttingrim of at least one of said circular knives has a hollow grinding. 26.The device according to claim 18, wherein rotational speeds of thecircular knives are about 20% higher than said web running speed of saidpaper web.